Terminal position assurance devices are commonly known in the electrical connector industry. Generally, there are two types of terminal position assurance devices, namely, a front-load type terminal position assurance device and a side/top load type terminal position assurance device.
For the front-load type terminal position assurance device, the terminal position assurance device effectively prevents a resiliently-biased lance member from deflecting within the female terminal connector when all of the female terminals are properly inserted into the female terminal connector. However, in the event that one or more of the female terminals are only partially inserted into the female terminal connector and, thus, improperly inserted thereinto, the terminal position assurance device might also prevent the resiliently-biased lance member from deflecting with the female terminal connector but, poor connectivity might result upon insertion of the male terminal into the female terminal. Thus, it is possible that the terminal position assurance device moves to its final lock position even though the female terminals are only partially and, thus, improperly inserted into the female terminal connector.
For the side/top load type terminal position assurance device, a channel must be formed across with female terminal connector with the female terminal connectors properly inserted therein. In the event that the female terminals are not properly inserted into the female terminal connector, as described above, the side/top load type terminal position assurance device cannot be inserted completely through the channel. Thus, it can be determined that one or more female terminals are not properly inserted into the female terminal connector. Only when all of the female terminals are properly inserted into the female terminal connector will the side/top load type terminal position assurance device extend through the female terminal connector. In this manner, it is possible to detect that the female terminals are not properly inserted into the female connector. However, the side/top load type terminal position assurance device and the female terminal connector is difficult to manufacture.